Hooking Win32 windows creation/resize/querying sizes - c++

Question

I'm trying to "stretch" an existing application.
The goal is to make an existing application become larger without changing the code of that application.
A cosntraint is that the stretched application will not "notice" it, so if the application query a created window size it'll see the original size and not the resized size.
I managed to resize the windows using SetWindowsHookEx:
HHOOK hMessHook = SetWindowsHookEx(WH_CBT,CBTProc, hInst, 0);
And:
LRESULT CALLBACK CBTProc( __in int nCode,
__in WPARAM wParam,
__in LPARAM lParam)
{
if (HCBT_CREATEWND == nCode)
{
CBT_CREATEWND *WndData = (CBT_CREATEWND*) lParam;
// Calculate newWidth and newHeight values...
WndData->lpcs->cx = newWidth;
WndData->lpcs->cy = newHeight;
}
CallNextHookEx(hMessHook, nCode, wParam, lParam);
}
The problem I'm facing is that I'm unable to the make the stretched application see the original sizes.
For example, if a .NET form is created:
public class SimpleForm : Form
{
public SimpleForm()
{
Width = 100;
Height = 200;
}
}
And later the size is queried:
void QuerySize(SimpleForm form)
{
int width = form.Width;
int height = form.Height;
}
I'd like width and height be 100 and 200 and not the resized values. I was unable to find the right hook which queries the size of an existing window.
What is the right way to hook window size querying?

Answer 1

Unfortunately, queries for window size aren't handled by messages -- they are direct API calls such as GetWindowRect -- so they can't be intercepted by standard Windows hooks. You might want to look into the Detours API, which allows you to hook arbitrary Win32 functions. (You can find a tutorial on Detours here)